Blood flow disorders can lead to numerous health and cosmetic problems for people. Relatively immobile patients, such as post-operative patients, the bedridden, and those individuals suffering from lymphedema and diabetes. Travelers confined to tight quarters during airline travel, for example, are particularly at risk for the development of thromboses, or blood clots due to decreased blood flow. Varicose veins are another disorder resulting from problems with patient blood flow. Varicose veins are often a symptom of an underlying condition called venous insufficiency. Normal veins have one-way valves that allow blood to flow upward only to return to the heart and lungs. A varicose vein has valves that are not functioning properly. The blood can flow upwards, but tends to pool in the vein because of valve dysfunction. The varicose veins bulge because they are filled with pooled blood. Although varicose veins are often a cosmetic concern, the condition also causes pain, leg heaviness, fatigue, itching, night cramps, leg swelling, and restless legs at night. Varicose vein disease can be treated with various nonsurgical techniques such as sclerotherapy or endovenous laser treatment (“EVLT”). In some cases enhanced blood flow is essential for quality of life, such as for those individuals suffering from RVD (peripheral vascular disease) and RLS (restless leg syndrome), or women undergoing reconstructive breast surgery suffering from arm pain and fatigue due to poor blood flow.
For some individuals the condition can also be treated by the nightly use of compression stockings. Compression stockings are elastic stockings that squeeze the veins and stop excess blood from flowing backward. These, and other known devices, tend to only provide an initial compression force at a low level that decreases over time upon continued deformation of the stocking.
Many athletes, whether professionals or lay persons, suffer from muscle soreness, pain and fatigue after exercise due to toxins and other workout by-products being released. Recent research has shown that compression garments may provide ergogenic benefits for athletes during exercise by enhancing lactate removal, reducing muscle oscillation, and positively influencing psychological factors. Some early research on compression garments has demonstrated a reduction in blood lactate concentration during maximal exercise on a bicycle ergometer. Later investigations have shown improved repeated jump power and increased vertical jump height. The suggested reasons for the improved jumping ability with compression garments include an improved warm-up via increased skin temperature, reduced muscle oscillation upon ground contact, and increased torque generated about the hip joint. Combined, these results show that compression garments may provide both a performance enhancement and an injury reduction role during exercises provoking high blood lactate concentrations or explosive-based movements.
Research has also shown that compression garments may promote blood lactate removal and therefore enhance recovery during periods following strenuous exercise. In one test, significant reduction in blood lactate levels in highly fit were observed in males wearing compression stockings following a bicycle ergometer test at 110% VO2max. Similar results were obtained in a later study in which a significant reduction in blood lactate concentration and an increased plasma volume was found in twelve elderly trained cyclists wearing compression garments following five minutes of maximal cycling. In another test, wearing compression garments during an 80 minute rest period following the five minutes of maximal cycling were shown to significantly increase (2.1%) performance during a subsequent maximal cycling test. It was suggested that increased removal of the metabolic by-products during intense exercise when wearing compression garments may help improve performance. These results suggest that wearing compression garments during recovery periods following high intensity exercise may enhance the recovery process both during and following intense exercise and therefore improve exercise performance.
Compression devices have also been used during recovery periods for athletes following strenuous activity. These devices are generally limited to the athlete's legs and typically comprise a series of inflatable bladders in a heel-to-thigh casing. An air pump inflates the series of bladders in a predetermined sequence to stimulate arterial blood flow through the athlete's legs. Compression devices of this type are extremely bulky, requiring that the athlete remain generally immobile, either seated or in a prone position.
More recently, improved compression devices have been described, as in U.S. Application Publication No. 2014/0081187, entitled COMPRESSION INTEGUMENT, by Wyatt et al. (the disclosure of which is incorporated herein by reference, in its entirety), and include comfortable and mobile devices. Such devices have incorporated shape memory materials and include a level of self-regulation. Yet, there remains a need for still better improved compression devices that yield more control of levels of constriction, are further self-regulating, and may be incorporated in additional therapies, such as to stimulate blood flow.